Tomato Cutin Deficient 1 (CD1) and putative orthologs comprise an ancient family of cutin synthase‐like (CUS) proteins that are conserved among land plants

Abstract

Summary The aerial epidermis of all land plants is covered with a hydrophobic cuticle that provides essential protection from desiccation, and so its evolution is believed to have been prerequisite for terrestrial colonization. A major structural component of apparently all plant cuticles is cutin, a polyester of hydroxy fatty acids. However, despite its ubiquity, the details of cutin polymeric structure and the mechanisms of its formation and remodeling are not well understood. We recently reported that cutin polymerization in tomato (Solanum lycopersicum) fruit occurs via transesterification of hydroxyacylglycerol precursors, catalyzed by the GDSL-motif lipase/hydrolase family protein (GDSL) Cutin Deficient 1 (CD1). Here we present additional biochemical characterization of CD1 and putative orthologs from Arabidopsis thaliana and the moss Physcomitrella patens, which represent a distinct clade of cutin synthases within the large GDSL super-family. We demonstrate that members of this ancient and conserved family of cutin synthase-like (CUS) proteins act as polyester synthases with negligible hydrolytic activity. Moreover, solution-state NMR analysis indicates that CD1 catalyzes the formation of primarily linear cutin oligomeric products in vitro. These results reveal a conserved mechanism of cutin polyester synthesis in land plants, and suggest that elaborations of the linear polymer, such as branching or cross-linking, may require additional, as yet unknown, factors.

MYB107 and MYB9 Homologs Regulate Suberin Deposition in Angiosperms

“…Cutin polymerization has recently received significant attention and yet still remains largely undescribed (Domínguez et al, 2015). While spontaneous polymerization of cutin monomers was considered, CUS proteins (which have been localized to the extracellular region) have been described to act as acyltransferase enzymes able to link cutin monomers (such as monoglycerols) (Yeats et al, 2012(Yeats et al, , 2014. In suberin polymer synthesis, SUS proteins may perform an analogous role, making use of monoglycerols and/or hydroxyl-alkyl ferulates as substrates.…”

“…Expression profiles of the genes encoding MYB proteins from Arabidopsis (AtMYB107 and AtMYB9, AT3G02940 and AT5G16770), tomato (SlMYB93, Solyc04g074170), apple (MdMYB53, MDP0000145757), grape (VvMYB107, VIT_16s0039g01710), potato (StMYB93, PGSC0003DMP400011365), and rice (OsMYB93, LOC_Os03g27090) are shown with the bait genes (GPAT5, ASFT, and CYP86B1) in Supplemental Figures 9A to 9G and illustrate the conservation of expression pattern of these regulators with the known suberin biosynthesis genes. Phylogenetic analysis of the identified GDSL-motif esterases found the clade to be a close relative of the cutin synthase (CUS) clade (Yeats et al, 2012(Yeats et al, , 2014 Genes upregulated in SlDCR-RNAi compared with the wild type and in the russeted 'Rugiada' clone compared with the regular skinned 'Reinders' were depicted in a heat map. For a full list of identified genes and the corresponding expression patterns, see Supplemental Data Sets 2 and 3 and Supplemental Table 2.…”

Diet of Arbuscular Mycorrhizal Fungi: Bread and Butter?

“…2-MAG is exported into the apoplast by ABCG transporters [87]. Finally, the cutin precursors are polymerized on the outer side of the polysaccharide cell wall by cutin synthase (CS), whereby the glycerol is released [78,88]. Proteins (transporters and enzymes) are indicated in blue.…”

Comprehensive Tissue-Specific Transcriptome Analysis Reveals Distinct Regulatory Programs during Early Tomato Fruit Development

“…Likewise, genes from the lipid metabolism and binding category were overrepresented in both cluster 29 (young fruit septum) and cluster 27 (ovary septum). These clusters comprised several genes encoding lipases containing the GDSL motif and lipid-transfer proteins; in addition, some genes in cluster 29 encode proteins related to cutin metabolism, including the tomato cutin synthase CUTIN DEFICIENT1 (Yeats et al, 2014) and homologs of Arabidopsis ECERIFERUM8 and CYP86A2, a member of the cytochrome p450 CYP86A subfamily, which are involved in fatty acid modification (Xiao et al, 2004;Lü et al, 2009).…”